Comparison: osmotic laxative versus stimulant laxative (PEG versus Lactulose)

OutcomeMeta- analysis detailsSummary Statisticsp (hetero) and I2Comments:Study qualityDirectnessImprecisionInconsistencyReporting BiasGRADE CommentsGRADE Evidence Rating
Global improvement of IBS symptoms (mean score)1 trial; 99 patients; from RCT; (long term maintenance design)MD=2.2 (95%CI 1.05, 3.35)statistically significant, in favour of PEG. Scale 1– 10, high score= good response. Lactulose: 5.20.Poor - patients could take other laxatives ad libIndirect setting- minor, secondary care OPDPreciseconsistent---Patients with chronic constipation, some may have had IBS; in secondary care. Attar 1999. Patients could take other laxatives during trial ad-lib.Low
No of patients using rescue microenemas1 trial; 115 patients; from RCT; (long term maintenance design)RR=0.48 (95%CI 0.25, 0.95)Statistically significant. More patients used microenemas in the lactulose group. NNT 6 for lactulose group rate of 35%GoodIndirect setting- minor, secondary care OPDFairly wide CIconsistent---Rescue medication. Patients with chronic constipation, some may have had IBS; in secondary care. Patients could take other laxatives during trial ad-lib.Low
No of patients not using rescue medication1 trial; 115 patients; from RCT; (long term maintenance design)RR=1.27 (95%CI 1.02, 1.59)Statistically significant. Favours PEG. NNT 6 for lactulose group rate of 65%GoodIndirect setting- minor, secondary care OPDPreciseconsistent---Rescue medication. Patients with chronic constipation, some may have had IBS; in secondary care. Patients could take other laxatives during trial ad-lib.Moderate
pain number of patients2 trials; 180 patients; from meta-analysis; (long term maintenance design)OR=0.55 (95%CI 0.25, 1.22)p=0.80; I2 =0%Not statistically significant. No heterogeneity.Poor - patients could take other laxatives ad libIndirect setting- minor, secondary care OPDFairly wide CIconsistentPoor - studies, industryPatients with chronic constipation, some may have had IBS; 1/2 in secondary care. In 1/2 patients could take other laxatives during trial ad- lib. 1/2 industry sponsoredLow
No of patients with bloating2 trials; 180 patients; from meta-analysis; (long term maintenance design)RR=0.63 (95%CI 0.39, 1.04)p=0.16; I2 =49.6%Not statistically significant, favours PEG. Some heterogeneity. May be dose dependent.Poor - patients could take other laxatives ad libIndirect setting- minor, secondary care OPDPreciseminor inconsistencyPoor - studies, industryPatients with chronic constipation, some may have had IBS; 1/2 in secondary care. In 1/2 patients could take other laxatives during trial ad- lib. 1/2 industry sponsoredLow
Stool freq2 trials; 180 patients; from meta-analysis; (long term maintenance design)WMD=0.27 (95%CI 0.09, 0.45)p=0.16; I2 =50%Statistically significant difference in stools per day in favour of PEG, some heterogeneityPoor - patients could take other laxatives ad libIndirect setting- minor, secondary care OPDPreciseminor inconsistencyPoor - studies, industryPatients with chronic constipation, some may have had IBS; 1/2 in secondary care. In 1/2 patients could take other laxatives during trial ad- lib. 1/2 industry sponsoredLow

From: Appendix F, Grading the evidence

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Copyright © 2008, Royal College of Nursing.

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